This invention relates to a kitchen appliance and in particular, to a stand mixer of the type which is not held by hand.
A stand mixer is a kitchen appliance which is used for mixing dough, batters, cake mixes and the like and may incorporate a power take off for driving other kitchen type appliance attachments such as a blender or mincer. The mixer is generally too heavy to be held by hand in use and has a frame designed to sit on a kitchen bench or table. The mixer has an electric motor which drives the beating or mixing implements through a gear train. A gear train being a series of gears or cogs which change the speed or orientation of a rotation. Traditionally, the gear train of a stand mixer contains a worm on the shaft of the motor. The worm drives a worm gear which as well as changing speed also changes the orientation of rotation from a horizontal axis to a vertical axis. In order to mass produce these gears for the gear train, the worm gear is made as a straight sided helical gear. This type of gear assembly is known to be noisy and to overcome this noise, the gear train is heavily coated with grease and covered by a heavy or thick cover to absorb some of the noise. Recently, when high speed motors were used, additional gearing between the worm and the motor shaft was introduced to keep the worm speed as low as possible to reduce the audible noise.
However, the mixer is still noisy and as other kitchen appliances become quieter, there is a strong desire for a quieter stand mixer, especially in the heavy duty deluxe range where smaller high speed motors are used to drive implements through a higher speed reduction gear train to maintain or increase output torque with a lighter motor.
It has been discovered that the worm gear is still responsible for a substantial amount of noise from the gear train of a stand mixer. With this in mind, the present invention aims to reduce the gear train noise of a stand mixer by utilizing a stand mixer with a quieter worm gear assembly.